Synergistic insecticidal compositions

ABSTRACT

The present invention provides a synergistic insecticidal composition comprising as essential active ingredients a neuronal sodium channel antagonist in combination with one or more compounds selected from the group consisting of pyrethroids, pyrethroid-type compounds, recombinant nucleopolyhedroviruses capable of expressing an insect toxin, organophosphates, carbamates, formamidines, macrocyclic lactones, amidinohydrazones, GABA antagonists and acetylcholine receptor ligands. 
     Also provided are methods for synergistic insect control and crop protection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Divisional of application Ser. No. 10/145,784, filed on May16, 2002, (pending), the entire disclosure of which is herewithincorporated by reference, which is a divisional application ofapplication Ser. No. 09/521,987, filed on Mar. 9, 2000 (now U.S. Pat.No. 6,479,543), the entire disclosure of which is herewith incorporatedby reference, which claims the benefit of provisional application Ser.No. 60/124,306 (filed Mar. 12, 1999) and Ser. No. 60/158,201 (filed onOct. 7, 1999), both abandoned, the entire disclosures of which areherewith incorporated by reference.

BACKGROUND OF THE INVENTION

Insecticidal agents and compositions have been developed to controlinsect pests such as agrohorticultural pests, hygienic pests, orwood-eating pests and in practice have been used as a single or a mixedagent. However, economically efficient and ecologically safe insectcontrol compositions are still being sought. Insecticidal compositionswhich allow for reduced effective dosage rates, increased environmentalsafety and lower incidence of insect resistance are highly desirable.Although the rotational application of insect control agents havingdifferent modes of action may be adopted for good pest managementpractice, this approach does not necessarily give satisfactory insectcontrol. Further, even though combinations of insect control agents havebeen studied, a high synergistic action has not always been found.Obtaining an insecticidal composition which demonstrates nocross-resistance to existing insecticidal agents, no toxicity problemsand little negative impact on the environment is extremely difficult.

Therefore, it is an object of this invention to provide a synergisticinsecticidal composition which demonstrates a high controlling effectwith concomittant reduced crop production cost and reduced environmentalload.

It is another object of this invention to provide methods forsynergistic insect control and enhanced crop protection.

SUMMARY OF THE INVENTION

The present invention provides a synergistic insecticidal compositioncomprising as essential active ingredients a synergistically effectiveamount of a neuronal sodium channel antagonist in combination with oneor more compounds selected from the group consisting of pyrethroids,pyrethroid-type compounds, recombinant nucleopolyhedroviruses capable ofexpressing an insect toxin, organophosphates, carbamates, formamidines,macrocyclic lactones, amidinohydrazones, GABA (gamma-aminobutyric acid)antagonists, and acetylcholine receptor ligands.

The present invention also provides a method for synergistic insectcontrol which comprises contacting said insect with a synergisticallyeffective amount of a neuronal sodium channel antagonist in combinationwith one or more compounds selected from the group consisting ofpyrethroids, pyrethroid-type compounds, recombinantnucleopolyhedroviruses capable of expressing an insect toxin,organophosphates, carbamates, formamidines, macrocyclic lactones,amidinohydrazones, GABA antagonists and acetylcholine receptor ligands.

The present invention further provides a method for the enhancedprotection of plants from infestation and attack by insects.

DETAILED DESCRIPTION OF THE INVENTION Definitions

“Acetylcholine receptor ligand compound” as used in this applicationmeans a compound which is capable of binding to the acetylcholinereceptor site.

“Group A” as used in this application means insecticidal

-   -   1) pyrethroid compounds;    -   2) pyrethroid-type compounds;    -   3) recombinant nucleopolyhedroviruses capable of expressing an        insect toxin;    -   4) organophosphate compounds;    -   5) carbamate compounds;    -   6) formamidine compounds;    -   7) macrocyclic lactone compounds;    -   8) amidinohydrazone compounds;    -   9) GABA antagonist compounds; and    -   10) acetylcholine receptor ligand compounds.

“Haloalkyl” as used in this application means an alkyl groupC_(x)H_(2x+1) having 1 to 2x+1 halogen atoms which may be the same ordifferent, Similarly, the terms “haloalkenyl”, “haloalkynyl”,“haloalkoxy”, “halophenyl” and the like mean mono- to perhalogensubstitution wherein the halogens may be the same or different.

“Halogen” as used in this application means Cl, Br, I or F.

“Neuronal sodium channel antagonist” as used in this application means acompound which is capable of preventing the ability of a neuron cell totransfer sodium ions across the cell membrane.

“Pyrethroid-type compounds” as used in this application means thosecompounds characterized by a non-ester linked aryl-phenoxybenzyl moiety.

“Synergism” as used in this application means a cooperative actionencountered in a combination of two or more biologically activecomponents in which the combined activity of the two or more componentsexceeds the sum of the activity of each component alone.

Surprisingly, it has now been found that a composition which comprises acombination of a neuronal sodium channel antagonist and a secondinsecticidal ingredient provides superior insect control at lower levelsof the combined active agents than may be achieved when the neuronalsodium channel antagonist or the second insecticidal ingredient isapplied alone.

As previously stated, the term neuronal sodium channel antagonistdesignates a compound which is capable of preventing the ability of aneuron cell to transfer sodium ions across the cell membrane. A neuroncell thus affected is unable to fire, resulting in paralysis, andultimately mortality, in the target host. Descriptions of neuronalsodium channel antagonists and their mode of action may be found inPesticide Biochemistry and Physiology, 60: 177-185 or Archives of InsectBiochemistry and Physiology, 37: 91-103.

Neuronal sodium channel antagonists include compounds such as thosedescribed in U.S. Pat. No. 5,543,573; U.S. Pat. No. 5,708,170; U.S. Pat.No. 5,324,837 and U.S. Pat. No. 5,462,938, (the description of which arehereby incorporated by reference) among other publications. Exemplary ofthe neuronal sodium channel antagonist compounds useful in thecomposition of this invention are those compounds having the structuralformula

wherein A is CR₄R₅ or NR₆;

-   -   W is O or S;    -   X, Y, Z, X′, Y′ and Z′ are each independently H; halogen; OH;        CN; NO₂; C₁-C₆alkyl optionally substituted with one or more        halogen, C₁-C₃alkoxy, C₁-C₃haloalkoxy, C₃-C₆cycloalkyl,        C₂-C₆alkenyloxy or sulfonyloxy groups;        -   C₁-C₆alkoxy optionally substituted with one or more halogen,            C₁-C₃alkoxy or C₃-C₆cycloalkyl groups;        -   C₁-C₆alkoxycarbonyl, C₃-C₆cycloalkylcarbonyloxy, phenyl            optionally substituted with one or more halogen, C₁-C₄alkyl,            or C₁-C₄alkoxy groups;        -   aminocarbonyloxy optionally substituted with one or more            C₁-C₃alkyl groups;        -   C₁-C₆alkoxycarbonyloxy; C₁-C₆alkylsulfonyloxy;        -   C₂-C₆alkenyl; or NR₁₂R₁₃;    -   m, p and q are each independently an integer of 1, 2, 3, 4, or        5;    -   n is an integer of 0, 1 or 2;    -   r is an integer of 1 or 2;    -   t is an integer of 1, 2, 3 or 4;    -   R, R₁, R₂, R₃, R₄ and R₅ are each independently H or C₁-C₄alkyl;    -   R₆ is H, C₁-C₆alkyl, C₁-C₆haloalkyl, C₁-C₆alkoxyalkyl,        C₁-C₆alkoxy, C₁-C₆haloalkoxy, C₂-C₆alkenyl, C₂-C₆alkynyl,        C₁-C₆alkylcarbonyl, C₁-C₆alkoxy-carbonyl, C₁-C₆alkylthio, or        C₁-C₆haloalkylthio;    -   R₇ and R₈ are each independently H; halogen; C₁-C₆alkyl;        C₁-C₆alkylcarbonyloxy; or phenyl optionally substituted with one        or more halogen, CN, NO₂, C₁-C₆alkyl, C₂-C₆halo-alkyl,        C₁-C₆alkoxy or C₁-C₆haloalkoxy groups;    -   R₉ and R₁₀ are each independently H, or C₁-C₄alkyl;    -   R₁₁ is H, C₁-C₆alkyl, C₁-C₆haloalkyl, C₁-C₄alkyl-carbonyl,        C₁-C₆alkoxycarbonyl, or C₁-C₆halo-alkoxycarbonyl;    -   R₁₂ and R₁₃ are each independently H or C₁-C₆alkyl;    -   G is H; C₁-C₆alkyl optionally substituted with one or more        halogen, C₁-C₄alkoxy, C₁-C₆haloalkoxy, CN, NO₂S(O)_(u)R₁₄,        COR₁₅, CO₂R₁₆, phenyl or C₃-C₆cycloalkyl groups;        -   C₁-C₆alkoxy; C₁-C₆haloalkoxy; CN; NO₂; S(O)_(u)R₁₇;        -   COR₁₈; CO₂R₁₉; phenyl optionally substituted with one or            more halogen, CN, C₁-C₃halo-alkyl, or C₁-C₃haloalkoxy            groups;        -   C₃-C₆cycloalkyl; or phenylthio;    -   Q is phenyl optionally substituted with one or more halogen, CN,        SCN, NO₂, S(O)_(u)R₂₀, C₁-C₄alkyl, C₁-C₄haloalkyl,        C₁-C₄alkoxyalkyl, C₁-C₆alkoxy, C₁-C₆haloalkoxy, or NR₂₁R₂₂        groups;    -   u is an integer of 0, 1 or 2;    -   R₁₄, R₁₅, R₁₆, R₁₈, R₁₉, R₂₁ and R₂₂ are each independently H or        C₁-C₆alkyl;    -   R₁₇ and R₂₀ are each independently C₁-C₆alkyl or C₁-C₆haloalkyl;    -   R₃₃ is CO₂R₃₄;    -   R₃₄ is H, C₁-C₆alkyl, C₁-C₆haloalkyl, phenyl or halophenyl; and        the dotted line configuration    -   C        N represents a double bond or a single bond (i.e. C—N or C═N);        or        a stereoisomer thereof.

Preferred neuronal sodium channel antagonists suitable for use in thecomposition of the invention are those compounds of formula I, II or IIIwherein the dotted line configuration C

N represents a double bond.

More preferred neuronal sodium channel antagonists suitable for use inthe inventive composition are those compounds of formula I or formulaIII wherein the dotted line configuration represents a double bond.

Particularly preferred neuronal sodium channel antagonists useful in thecomposition of the invention are those compounds of formula I or formulaIII wherein W is O; X is trifluoromethoxy and is in the 4-position; Y istrifluoromethyl and is in the 3-position; Z is CN and is in the4-position; A is CH₂; n is 0; m, p and q are each 1; R and R₁ are eachH; Z, is C₁; R₃₃ and G are each CO₂CH₃; Q is p-(trifluoromethoxy)phenyl;and the dotted line configuration C

N represents a double bond; or a stereoisomer thereof.

Further neuronal sodium channel antagonist compounds include thosedescribed in U.S. Pat. No. 5,116,850 and U.S. Pat. No. 5,304,573, (thedescription of which are hereby incorporated by reference) among otherpublications. Exemplary of further neuronal sodium channel antagonistcompounds suitable for use in the composition of the invention are thosecompounds having structural formula

wherein W is O or S;

-   -   X″ and Y″ are each independently H; halogen; CN; SCN; C₁-C₆alkyl        optionally substituted with one or        -   more halogen, NO₂, CN, C₁-C₄alkoxy, C₁-C₄alkylthio, phenyl,            halophenyl, C₁-C₄alkylsulfonyl, C₁-C₄haloalkylsulfonyl, or            C₁-C₄alkoxycarbonyl groups;    -   C₂-C₄alkenyl; C₂-C₄haloalkenyl; C₂-C₄alkynyl; C₂-C₄haloalkynyl;        C₃-C₆cycloalkyl; C₃-C₆halocycloalkyl; phenyl optionally        substituted        -   with one or more halogen, CN, NO₂, C₁-C₄alkyl,            C₁-C₄haloalkyl, C₁-C₄alkoxy, C₁-C₄haloalkoxy,            C₁-C₄alkylthio, C₁-C₄alkylsulfonyl or C₁-C₄haloalkylsulfonyl            groups;    -   C₁-C₄alkylcarbonyl; C₁-C₄haloalkylcarbonyl; or NR₂₈R₂₉;    -   m is an integer of 1, 2, 3, 4 or 5;    -   G′ is phenyl optionally substituted with one or more groups        which may be the same or different selected from X″;        -   a 5-membered heteroaromatic ring containing one or two            heteroatoms selected from 0 or 1 oxygen, 0 or 1 sulfur and            0, 1 or 2 nitrogen atoms said 5-membered heteroaromatic ring            being attached via carbon and being optionally substituted            with one or more groups which may be the same or different            selected from X″; or        -   a 6-membered heteroaromatic ring containing one or two            heteroatoms selected from 0 or 1 oxygen, 0 or 1 sulfur and            0, 1 or 2 nitrogen atoms said 6-membered heteroaromatic ring            being attached via carbon and being optionally substituted            with one or more groups which may be the same or different            selected from X″;    -   Q′ is H; C₁-C₆alkyl optionally substituted with one or more        halogen, CN, C₁-C₃alkoxy, C₁-C₆alkoxycarbonyl, or phenyl        optionally substituted with one or more halogen, CN, NO₂,        C₁-C₄alkyl, C₁-C₄haloalkyl, C₁-C₄alkylsulfonyl or        C₁-C₄alkylsulfinyl groups;        -   C₂-C₆alkenyl; C₂-C₆alkynyl; or phenyl optionally substituted            with one to three groups, which may be the same or            different, selected from X″;    -   R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, R₂₈ and R₂₉ are each independently H or        C₁-C₄alkyl; and the dotted line configuration C        N represents a double bond or a single bond (i.e. C—N or C═N);        or a stereoisomer thereof.

Further preferred neuronal sodium channel antagonist compounds of theinvention are those compounds of formula IV or V wherein the dotted lineconfiguration C

N represents a double bond.

Other preferred neuronal sodium channel antagonist compounds suitablefor use in the composition of the invention are those compounds offormula IV or V wherein W is 0; X″ and Y″ are each independently H orC₁-C₆halo-alkyl; m is 1; R₂₃, R₂₄, R₂₅, R₂₆ and R₂₇ are each H; G isphenyl optionally substituted with one or more halogen atoms; Q′ ishalophenyl or C₁-C₄alkyl optionally substituted with one phenyl orhalophenyl group; and the dotted line configuration C

N represents a double bond; or a stereoisomer thereof.

The second active ingredient of the insecticidal composition of theinvention includes one or more compounds selected from Group A:

1) pyrethroid compounds which are known to be insecticidally active suchas cypermethrin, cyhalothrin, cyfluthrin, permethrin or the like;

2) pyrethroid-type compounds which are known to be insecticidally activesuch as ethofenprox, silafluofen, or the like;

3) recombinant nucleopolyhedroviruses capable of expressing an insecttoxin, preferably an insect neurotoxin such as Androctonus australisinsect toxin (AaIT), for example HzNPV-AaIT;

4) organophosphate compounds which are known to be insecticidally activesuch as profenofos, acephate, sulprofos, malathion, diazinon, methylparathion, terbufos, or the like;

5) carbamate compounds which are known to be insecticidally active suchas methomyl, thiodicarb, fenothiocarb, or the like;

6) formamidine compounds which are known to be insecticidally activesuch as amitraz, chlordimeform, chlorfenamidine, or the like;

7) macrocyclic lactone compounds which are known to be insecticidallyactive such as spinosad, avermectin, emamectin, milbemectin, nemadectin,moxidectin or the like;

8) amidinohydrazone compounds which are known to be insecticidallyactive such as hydramethylnon;

9) GABA antagonist compounds which are known to be insecticidallyeffective such as fipronil, endosulfan, or the like;

10) acetylcholine receptor ligand compounds which are known to beinsecticidally effective such as imidacloprid, acetamiprid, nitenpyram,thiamethoxam, or the like.

Descriptions of the above-listed commercially available compounds may befound in The Pesticide Manual, 11th Edition, British Crop ProtectionCouncil (1997) among other publications. Descriptions of recombinantnucleopolyhedroviruses capable of expressing an insect toxin includeTreacy et al, Proceedings Beltwide Cotton Conference (1999), pp1076-1083.

Preferred compositions of the invention are those compositions having aneuronal sodium channel antagonist compound of formula I or formula IIIin combination with one or more compounds selected from Group A.

More preferred compositions of the invention are those compositionshaving a formula I or formula III compound wherein W is O; X istrifluoromethoxy and is in the 4-position; Y is trifluoromethyl and isin the 3-position; Z is CN and is in the 4-position; A is CH₃; n is 0;m, p and q are each independently 1; R and R₁, are each independently H;Z′ is Cl; R₃₃ and G are each independently CO₂CH₃; Q isp-(trifluoromethoxy)phenyl; and the dotted line configuration C

N represents a double bond in combination with one or more compoundsselected from Group A.

Each of the compounds of formula I, II, III, IV and V embody assymetriccenters which may be represented in the stereoisomeric R-form or S-form.The present invention also includes the R-form, the S-form or mixturescomprising the R-form and the S-form in an arbitrary ratio. Forcompounds of formula III, the S-form is preferred.

Advantageously, the neuronal sodium-channel antagonist compound offormula I, II, III, IV or V or a mixture thereof may be formulated witha second insecticidally effective ingredient and optionally othercustomary formulation adjuvants. Said formulation may be dispersed in asolid or liquid diluent for application to the insect, its food supply,breeding ground or habitat as a dilute spray or as a solid dust or dustconcentrate.

The active ingredients of the inventive composition may also beformulated separately as a wettable powder, emulsifiable concentrate,aqueous or liquid flowable, suspension concentrate or any one of theconventional formulations used for insect control agents and tank-mixedin the field with water or other inexpensive liquid for application as aliquid spray mixture. The separately formulated compositions may also beapplied sequentially.

Advantageously, the composition of the invention may be formulated as abait composition comprising a synergistically effective amount of acombination of a neuronal sodium channel antagonist plus one or morecompounds selected from Group A and a solid or liquid edible nutritivesubstance. A preferred bait composition may contain by weight about0.01% to 20% active ingredients, preferably a neuronal sodium channelantagonist in combination with hydramethylnon.

In actual practice, the composition of the invention may be applied tothe plant foliage or plant stem or to the insect habitat or to the locusof a hygienic pest as a dilute spray prepared from any of the above-saidformulations. The ratio of the essential active ingredients of thecomposition of the invention is about 1 weight part of a neuronal sodiumchannel antagonist to about 0.01-100 weight parts of one or morecompounds selected from Group A.

The compositions of the invention are superior insecticidal compositionsand are especially useful for the control of agrohorticultural pests,hygienic pests or wood-eating pests. Said compositions are highlyeffective for the protection of growing and harvested plants including:leguminous crops such as soybeans, snap beans, peas, wax beans and thelike as well as cotton, forage crops, cole crops, leafy vegetables,tobacco, hops, tomatoes, potatoes, flowering ornamentals such aschrysanthemums, vine crops such as grapes, squash, pumpkin or melon andfruit trees such as cherry, peach, apple or citrus, from the ravages ofinsects.

The synergistic insecticidal composition of the invention is found to behighly active against a wide variety of lepidopteran and coleopteraninsects such as Helicoverpa zea (cotton bollworm), Heliothis virescens(tobacco budworm), Leptinotarsa decemlineata (Colorado potato beetle),Diabrotica spp. (corn rootworm) and the like.

Beneficially, the composition of the invention may be useful for theprevention and control of hygienic or public health pests such as:Diptera, e.g. houseflies, mosquitoes, or the like; Hymenoptera, e.g.ants, parasitic wasps, wasps or the like; Blattaria, e.g. cockroaches;or the like.

Further, the compositions of the invention may be particularly usefulfor the prevention and control of wood-eating insects such as termites(Isoptera), carpenter ants (Hymenoptera), wood-destroying beetles(Coleoptera) or the like.

These and other advantages of the invention may become more apparentfrom the examples set forth herein below. These examples are providedmerely as illustrations of the invention and are not intended to beconstrued as a limitation thereof.

EXAMPLE 1 Evaluation of the Synerqistic Insecticidal Effect of aCombination of a Neuronal Sodium Channel Antagonist Plus a SecondInsecticide

In this evaluation, Heliothis zea (cotton bollworm), Heliothis virescens(tobacco budworm) and pyrethroid-resistant Heliothis virescens larvaeused are obtained from laboratory colonies. Pyrethroid-resistant H.virescens are derived from the PEG-strain [Campannola & Plapp,Proceedings of Beltwide Cotton Conference (1988)].

Cotton leaves are immersed in 1:1 v/v, acetone/water solutions of testcompound, or solutions of a combination of test compounds for a periodof about 3 seconds. Following immersion, leaves are allowed to air-dryfor 2-3 hours. Plastic bioassay trays containing multiple open-facedwells (4.0×4.0×2.5 cm) are used as the test arenas. Cut portions of atreated leaf, a moistened cotton dental wick and a single third-instarlarva are placed into each well, covered with an adhesive vented clearplastic sheet and held under constant fluorescent light at about 27° C.for a predetermined period of time. Larval mortality/morbidity isevaluated at 5 days after treatment. All treatments are replicated 4-5fold in a randomized complete block design with 16-32 larvae pertreatment. Using conventional log-probit analysis, the LC₅₀ of eachtreatment is determined.

Using the above protocol, a neuronal sodium channel antagonist (CompoundA) may be evaluated alone at dose rates of 0.1 ppm, 1.0 ppm and 10.0 ppmand in combination with 1.0 ppm of a second insecticidal compound.Treatments which may be used are shown in Table I.

TABLE I Second Dose Compound A¹ Active Rate Dose Rate Compound (ppm)(ppm) (ppm) (ppm) (ppm) cypermethrin 0 0 0.1 1.0 10.0 1.0 0 0.1 1.0 10.0amitraz 0 0 0.1 1.0 10.0 1.0 0 0.1 1.0 10.0 fipronil 0 0 0.1 1.0 10.01.0 0 0.1 1.0 10.0 acetamiprid 0 0 0.1 1.0 10.0 1.0 0 0.1 1.0 10.0spinosad 0 0 0.1 1.0 10.0 1.0 0 0.1 1.0 10.0 thiodicarb 0 0 0.1 1.0 10.01.0 0 0.1 1.0 10.0 ¹Compound A = formula Ia neuronal sodium channelantagonist

EXAMPLE 2 Evaluation of the Synersistic Insecticidal Effect Of aCombination Of A Neuronal Sodium Channel Antagonist Plus anAmidinohydrazone

In this evaluation, adult male German cockroaches (Blattella germanica)are used. For each test, a 4.0 g portion of ground Purina Dog Chow(Hi-Pro Glob) is treated with an acetone solution of test compound aloneor in combination with a second test compound. After treatment, theacetone is evaporated and the treated dog chow is placed in a ¾ ozplastic cup which is placed in a harborage made of folded sheets ofblotter paper placed in a plastic box (16″L×11″W×6″H). The plastic box(test arena) is also fitted with a 1 oz narrow mouth bottle with 2dental wicks inserted at the mouth. A control box is prepared in thesame manner using ground dog chow which has been treated with reagentgrade acetone. Each treatment is replicated three times. Into each testarena are placed 20 healthy adult male cockroaches which have beenreared in an insectary. The test arenas are then stored at 76° F. andmortality is determined daily by visual examination. The data obtainedare shown in Table 11.

TABLE II % Mortality Test % Active Days After Treatment CompoundIngredient 3 4 5 6 7 8 A¹ 0.05 0 0 0 0 0 0 A  0.10 1.7 11.7 11.7 11.718.3 18.3 A  0.50 5.0 5.0 5.0 5.0 5.0 5.0 B² 1.00 0 5.0 28.3 71.7 90.093.3 A + B 0.05 + 1.0 0 20.0 41.7 81.7 95.0 98.3 A + B 0.10 + 1.0 0 21.751.7 88.3 95.0 95.0 A + B 0.50 + 1.0 16.7 58.3 80.0 95.0 98.3 100.0Control 0   0 1 .7 3.3 3.3 3.3 5.0 ¹Compound A = formula Ia neuronalsodium channel antagonist ²Compound B = hydramethylnon

As can be seen from the data shown in Table II, combinations of aneuronal sodium channel antagonist plus an amidinohydrazone insecticidedemonstrate synergistic insect control.

EXAMPLE 3 Evaluation of the Synergistic Insecticidal Effect Of aCombination Of A Neuronal Sodium Channel Antagonist Plus A RecombinantNucleopolyhedrovirus Capable of Expressing An Insect Toxin

In this evaluation, Helicoverpa zea (cotton bollworm) larvae areobtained from a laboratory colony. Test compounds are dissolved in 1:1v/v acetone/water. Plastic bioassay trays (C-D International, Pitman,N.J.) are used as test arenas. Each tray contains 32 open-faced wells,4.0×4.0×2.5 cm. A portion (5 ml) of a wheat germ-soybean flour-basedartificial diet (Southland Products, Lake Village, Ark.) is poured intoeach well. After the diet hardened, 0.4 ml of test solution is pipettedonto the diet surface in each well. Test solutions are evenly spreadover surfaces of diet by picking up the tray and gently tilting it fromside to side. Trays are then held in a vented area for about 2 h, untilwater is no longer pooled on diet surfaces. A single 4-day-old H. zealarva is then placed on the surface of diet in each well. After larvalinfestation, each well is covered with an adhesive, vented, clearplastic sheet.

All test arenas are held under constant fluorescent light and atemperature of about 27° C. for duration of the assay. Larval mortalityis determined at 2, 3, 4 and 7 days after treatment. A larva wasconsidered to be dead if it exhibited little to no movement, even afterbeing shaken in the diet tray. A total of 32 insects were tested foreach treatment. The data obtained are shown in Table III.

TABLE III Conc. of % Mortality Test Active Days After Treatment CompoundIngredient 2 3 4 7 A¹ 0.1 ppm 43.8 46.9 53.1 53.1 B² 1000 OB³/ml 3.134.4 50.5 62.5 B  500 OB/ml 0.0 9.4 18.8 40.6 B  100 OB/ml 3.1 3.1 3.115.6 A + B  0.1 + 1000 87.5 90.6 93.8 96.9 A + B 0.1 + 500 75.0 78.184.4 87.5 A + B 0.1 + 100 62.5 75.0 75.0 78.1 Control 0 3.1 3.1 3.1 3.1¹Compound A = formula Ia neuronal sodium channel antagonist ²Compound B= HzNPV-AaIT, Helicoverpa zea Nucleopolyhedrovirus which expressesAndroctonus australis insect toxin ³OB = viral occlusion bodies

As can be seen from the data shown in Table III, combinations of aneuronal sodium channel antagonist plus a recombinantnucleopolyhedrovirus which is capable of expressing an insect toxindemonstrate synergistic insect control.

1.-33. (canceled)
 34. A synergistic insecticidal composition comprisinga synergistically effective amount of a neuronal sodium channelantagonist in combination with one or more formamidine compounds,wherein the neuronal sodium channel antagonist is a compound of formula(I) or (V)

wherein A is CR₄R₅ or NR₆; W is O or S; X, Y and Z, are eachindependently H; halogen; OH; CN; NO₂; C₁-C₆alkyl optionally substitutedwith one or more halogen, C₁-C₃alkoxy, C₁-C₃haloalkoxy, C₃-C₆cycloalkyl,C₂-C₆alkenyloxy or sulfonyloxy groups; C₁-C₆alkoxy optionallysubstituted with one or more halogen, C₁-C₃alkoxy or C₃-C₆cycloalkylgroups; C₁-C₆alkoxycarbonyl, C₃-C₆cycloalkylcarbonyloxy, phenyloptionally substituted with one or more halogen, C₁-C₄alkyl, orC₁-C₄alkoxy groups; aminocarbonyloxy optionally substituted with one ormore C₁-C₃alkyl groups; C₁-C₆alkoxycarbonyloxy; C₁-C₆alkylsulfonyloxy;C₂-C₆alkenyl; or NR₁₂R₁₃; m, p and q are each independently an integerof 1, 2, 3, 4, or 5; n is an integer of 0, 1 or 2; r is an integer of 1or 2; t is an integer of 1, 2, 3 or 4; R, R₁, R₂, R₃, R₄ and R₅ are eachindependently H or C₁-C₄alkyl; R₆ is H, C₁-C₆alkyl, C₁-C₆haloalkyl,C₁-C₆alkoxyalkyl, C₁-C₆alkoxy, C₁-C₆haloalkoxy, C₂-C₆alkenyl,C₂-C₆alkynyl, C₁-C₆alkylcarbonyl, C₁-C₆alkoxycarbonyl, C₁-C₆alkylthio,or C₁-C₆haloalkylthio; R₇ and R₈ are each independently H; halogen;C₁-C₆alkyl; C₁-C₆alkylcarbonyloxy; or phenyl optionally substituted withone or more halogen, CN, NO₂, C₁-C₆alkyl, C₂-C₆haloalkyl, C₁-C₆alkoxy orC₁-C₆haloalkoxy groups; R₉ and R₁₀ are each independently H, orC₁-C₄alkyl; R₁₁ is H, C₁-C₆alkyl, C₁-C₆haloalkyl, C₁-C₄alkylcarbonyl,C₁-C₆alkoxycarbonyl, or C₁-C₆haloalkoxycarbonyl; R₁₂ and R₁₃ are eachindependently H or C₁-C₆alkyl; Y″ is H; halogen; CN; SCN; C₁-C₆alkyloptionally substituted with one or more halogen, NO₂, CN, C₁-C₄alkoxy,C₁-C₄alkyl-thio, phenyl, halophenyl, C₁-C₄alkylsulfonyl,C₁-C₄haloalkyl-sulfonyl, or C₁-C₄alkoxycarbonyl groups; C₂-C₄alkenyl;C₂-C₄haloalkenyl; C₂-C₄alkynyl; C₂-C₄haloalkynyl; C₃-C₆cycloalkyl;C₃-C₆halocycloalkyl; phenyl optionally substituted with one or morehalogen, CN, NO₂, C₁-C₄alkyl, C₁-C₄haloalkyl, C₁-C₄alkoxy,C₁-C₄haloalkoxy, C₁-C₄alkylthio, C₁-C₄alkylsulfonyl orC₁-C₄haloalkylsulfonyl groups; C₁-C₄alkylcarbonyl;C₁-C₄haloalkylcarbonyl; or NR₂₈R₂₉; m is an integer of 1, 2, 3, 4 or 5;G′ is phenyl optionally substituted with one or more groups which may bethe same or different selected from Y″; a 5-membered heteroaromatic ringcontaining one or two heteroatoms selected from 0 or 1 oxygen, 0 or 1sulfur and 0, 1 or 2 nitrogen atoms said 5-membered heteroaromatic ringbeing attached via carbon and being optionally substituted with one ormore groups which may be the same or different selected from Y″; or a6-membered heteroaromatic ring containing one or two heteroatomsselected from 0 or 1 oxygen, 0 or 1 sulfur and 0, 1 or 2 nitrogen atomssaid 6-membered heteroaromatic ring being attached via carbon and beingoptionally substituted with one or more groups which may be the same ordifferent selected from Y″; Q′ is H; C₁-C₆alkyl optionally substitutedwith one or more halogen, CN, C₁-C₃alkoxy, C₁-C₆alkoxycarbonyl, orphenyl optionally substituted with one or more halogen, CN, NO₂,C₁-C₄alkyl, C₁-C₄haloalkyl, C₁-C₄alkylsulfonyl or C₁-C₄alkylsulfinylgroups; C₂-C₆alkenyl; C₂-C₆alkynyl; or phenyl optionally substitutedwith one to three groups, which may be the same or different, selectedfrom Y″; R₂₆, R₂₇, R₂₈ and R₂₉ are each independently H or C₁-C₄alkyl;and the dotted line configuration C

N represents a double bond or a single bond; or a stereoisomer thereof.35. The composition according to claim 34 wherein the neuronal sodiumchannel antagonist is the compound of formula (I).
 36. The compositionaccording to claim 34 wherein the neuronal sodium channel antagonist isthe compound of formula (V).
 37. The composition according to claim 34wherein the dotted line configuration C

N represents a double bond.
 38. The composition according to claim 37wherein W is O; X is trifluoromethoxy and is in the 4-position; Y istrifluoromethyl and is in the 3-position; Z is CN and is in the4-position; A is CH₂; n is 0; m, p and q are each 1; R and R₁ are eachindependently H.
 39. The composition according to claim 38 wherein theone or more formamidine compounds are selected from the group consistingof amitraz, chlordimeform and chlorfenamidine.
 40. The compositionaccording to claim 34 wherein the one or more formamidine compounds areselected from the group consisting of amitraz, chlordimeform andchlorfenamidine.
 41. A method for synergistic insect control whichcomprises contacting said insects with a synergistically effectiveamount of a neuronal sodium channel antagonist in combination with oneor more insecticidally active formamidine compounds, wherein theneuronal sodium channel antagonist is a compound of formula (I) or (V)

wherein A is CR₄R₅ or NR₆; W is O or S; X, Y and Z, are eachindependently H; halogen; OH; CN; NO₂; C₁-C₆alkyl optionally substitutedwith one or more halogen, C₁-C₃alkoxy, C₁-C₃haloalkoxy, C₃-C₆cycloalkyl,C₂-C₆alkenyloxy or sulfonyloxy groups; C₁-C₆alkoxy optionallysubstituted with one or more halogen, C₁-C₃alkoxy or C₃-C₆cycloalkylgroups; C₁-C₆alkoxycarbonyl, C₃-C₆cycloalkylcarbonyloxy, phenyloptionally substituted with one or more halogen, C₁-C₄alkyl, orC₁-C₄alkoxy groups; aminocarbonyloxy optionally substituted with one ormore C₁-C₃alkyl groups; C₁-C₆alkoxycarbonyloxy; C₁-C₆alkylsulfonyloxy;C₂-C₆alkenyl; or NR₁₂R₁₃; m, p and q are each independently an integerof 1, 2, 3, 4, or 5; n is an integer of 0, 1 or 2; r is an integer of 1or 2; t is an integer of 1, 2, 3 or 4; R, R₁, R₂, R₃, R₄ and R₅ are eachindependently H or C₁-C₄alkyl; R₆ is H, C₁-C₆alkyl, C₁-C₆haloalkyl,C₁-C₆alkoxyalkyl, C₁-C₆alkoxy, C₁-C₆haloalkoxy, C₂-C₆alkenyl,C₂-C₆alkynyl, C₁-C₆alkylcarbonyl, C₁-C₆alkoxycarbonyl, C₁-C₆alkylthio,or C₁-C₆haloalkylthio; R₇ and R₈ are each independently H; halogen;C₁-C₆alkyl; C₁-C₆alkylcarbonyloxy; or phenyl optionally substituted withone or more halogen, CN, NO₂, C₁-C₆alkyl, C₂-C₆haloalkyl, C₁-C₆alkoxy orC₁-C₆haloalkoxy groups; R₉ and R₁₀ are each independently H, orC₁-C₄alkyl; R₁₁ is H, C₁-C₆alkyl, C₁-C₆haloalkyl, C₁-C₄alkylcarbonyl,C₁-C₆alkoxycarbonyl, or C₁-C₆haloalkoxycarbonyl; R₁₂ and R₁₃ are eachindependently H or C₁-C₆alkyl; Y″ is H; halogen; CN; SCN; C₁-C₆alkyloptionally substituted with one or more halogen, NO₂, CN, C₁-C₄alkoxy,C₁-C₄alkyl-thio, phenyl, halophenyl, C₁-C₄alkylsulfonyl,C₁-C₄haloalkyl-sulfonyl, or C₁-C₄alkoxycarbonyl groups; C₂-C₄alkenyl;C₂-C₄haloalkenyl; C₂-C₄alkynyl; C₂-C₄haloalkynyl; C₃-C₆cycloalkyl;C₃-C₆halocycloalkyl; phenyl optionally substituted with one or morehalogen, CN, NO₂, C₁-C₄alkyl, C₁-C₄haloalkyl, C₁-C₄alkoxy,C₁-C₄haloalkoxy, C₁-C₄alkylthio, C₁-C₄alkylsulfonyl orC₁-C₄haloalkylsulfonyl groups; C₁-C₄alkylcarbonyl;C₁-C₄haloalkylcarbonyl; or NR₂₈R₂₉; m is an integer of 1, 2, 3, 4 or 5;G′ is phenyl optionally substituted with one or more groups which may bethe same or different selected from Y″; a 5-membered heteroaromatic ringcontaining one or two heteroatoms selected from 0 or 1 oxygen, 0 or 1sulfur and 0, 1 or 2 nitrogen atoms said 5-membered heteroaromatic ringbeing attached via carbon and being optionally substituted with one ormore groups which may be the same or different selected from Y″; or a6-membered heteroaromatic ring containing one or two heteroatomsselected from 0 or 1 oxygen, 0 or 1 sulfur and 0, 1 or 2 nitrogen atomssaid 6-membered heteroaromatic ring being attached via carbon and beingoptionally substituted with one or more groups which may be the same ordifferent selected from Y″; Q′ is H; C₁-C₆alkyl optionally substitutedwith one or more halogen, CN, C₁-C₃alkoxy, C₁-C₆alkoxycarbonyl, orphenyl optionally substituted with one or more halogen, CN, NO₂,C₁-C₄alkyl, C₁-C₄haloalkyl, C₁-C₄alkylsulfonyl or C₁-C₄alkylsulfinylgroups; C₂-C₆alkenyl; C₂-C₆alkynyl; or phenyl optionally substitutedwith one to three groups, which may be the same or different, selectedfrom Y″; R₂₆, R₂₇, R₂₈ and R₂₉ are each independently H or C₁-C₄alkyl;and the dotted line configuration C

N represents a double bond or a single bond; or a stereoisomer thereof.42. The method according to claim 41, wherein the neuronal sodiumchannel antagonist is the compound of formula (I).
 43. The methodaccording to claim 41, wherein the neuronal sodium channel antagonist isthe compound of formula (V).
 44. The method according to claim 41,wherein the dotted line configuration C

N represents a double bond.
 45. The method according to claim 44,wherein W is O; X is trifluoromethoxy and is in the 4-position; Y istrifluoromethyl and is in the 3-position; Z is CN and is in the4-position; A is CH₂; n is 0; m, p and q are each 1; R and R₁ are eachindependently H.
 46. The method according to claim 45, wherein the oneor more formamidine compounds are selected from the group consisting ofamitraz, chlordimeform and chlorfenamidine.
 47. The method according toclaim 41, wherein the one or more formamidine compounds are selectedfrom the group consisting of amitraz, chlordimeform and chlorfenamidine.48. The method according to claim 41, wherein the insect is selectedfrom the group consisting of Blattaria, Isoptera, Diptera, andHymenoptera.
 49. The method according to claim 48, wherein the insectsare lepidopteraor coleoptera.
 50. A method for protecting a plant frominfestation and attack by insects which comprises applying to thefoliage or stem of said plant a synergistically effective amount of acomposition according to claim
 34. 51. The composition according toclaim 50, wherein the dotted line configuration C

N represents a double bond; W is O; X is trifluoromethoxy and is in the4-position; Y is trifluoromethyl and is in the 3-position; Z is CN andis in the 4-position; A is CH₂; n is 0; m, p and q are each 1; R and R₁are each independently H.
 52. The method according to claim 51, whereinthe one or more formamidine compounds are selected from the groupconsisting of amitraz, chlordimeform and chlorfenamidine.
 53. The methodaccording to claim 50, wherein the one or more formamidine compounds areselected from the group consisting of amitraz, chlordimeform andchlorfenamidine.